The letter from Sheriff David Gee essentially tells store owners about a new law that will make many of those substances illegal.

Some were not too happy about the attention.

With news cameras rolling, the owner of a Shell station convenience store on Sheldon Rd. was clearly less than thrilled with his visit from deputies with news cameras not far behind. His was one of hundreds of liquor stores, bars and quick stops getting the warning letter this week.

"You get that one percent that are irate that we're here. That we have some other agenda going on. And that's truly not the case," said Deputy Phil Acaba.

The store clerks and owners are encouraged to willingly hand over the substances to deputies now, before they become contraband.

"They have some options that they can surrender the substance, but once the law is signed we will take appropriate law enforcement action if they're found to be in violation," said Maj. Tom Feeney.

The bill, expected to be signed by Gov. Rick Scott, also presents law enforcement with a major challenge.

As quickly as the products become illegal, deputies admit manufacturers will almost certainly tweak the chemical formula... just enough to skirt the law. All in the name of money.

One store owner told Major Feeney it will hurt business.

"He did on average $30,000 a month, and his profit was 70%."

"They just gave us a warning," said Sudha Patel, whose store on North Dale Mabry was visited last week.

Patel says she's happy to comply. She doesn't like the statistics that show the number of kids being harmed by the counterfeit cannabis is skyrocketing.

"Yeah, I've heard of a lot of accidents and that kind," said Patel.

How fast is the number of incidents growing?

"In the first seven months of last year alone that number went from 303 to more than 4,700. And that was as of October 2011," said Maj. Feeney.

By the time Patel got her warning letter from the sheriff's office, she says she's already cleared the synthetic pot off her shelves. She anticipated that it would become illegal when the legislature passed the bill two weeks ago.

"That's not good stuff, you know," she said.

Again, these were just letters of warning. But the sheriff's office says once that bill has been signed, there will be no more warnings or grace periods.